This invention proposes a rotor for cooling pumps, in particular for marine engine pumps and the relevant manufacturing process.
More particularly the rotor according to the invention, which comprises a core to be keyed on a shaft connected with engine means and a plurality of radial tabs in a flexible material, is characterized in that said core and said tabs are both made of rubber or a similar material having different hardness.
More specifically the core is made of ebonized rubber, in particular a mixture of neoprene, nitrile, PVC and Kevlar®.
It is obtained a rotor which combines the features of the toughness distinguishing the rotors with a metallic core with those of lightness and wearproof distinguishing the rotors in synthetic material.
The invention fits into the sector of the cooling pumps of the type used on marine engines.
Generally these pumps comprise a rotor provided with a plurality of radial tabs, of flexible material, eccentrically assembled inside a chamber and put in rotation around its own axis.
The rotors of this type, known at present, are substantially divided into two typologies: those with a metallic core and those with a core in synthetic material.
In the rotors with metallic core the outer portion of the rotor body and its tabs are of flexible material, generally neoprene, injected on a core customarily made of brass, consisting of a substantially annular body having a scot for mounting it on a shaft connected with engine means.
With this type of rotor inconveniences often take place due to the corrosion and wear to which the metal is subject, when it comes in contact with the salty water and other polluting substances.
To avoid this inconvenience, rotors have been developed wherein the core consists of a cage of synthetic material, in particular nylon, charged with glass fiber, a core on which the outer portion in neoprene is then injected.
This second solution shows however the inconvenience of a remarkable brittleness with the consequent ease of breakage of the said rotor.
In the sector it is felt the need of a rotor which combines the features of lightness and wearproof of the rotors provided with a nylon core, but which results as strong and resistant as the rotors provided with a metallic core.